Saab 2000 9-5 - Manual (Page 170)

170 Car care and technical information
ORVR (Onboard Refueling Vapor
Recovery)
Hydrocarbon vapors formed when refueling
will be recovered by the car and not
released into the atmosphere. The hydro-
carbons are absorbed in a evaporative
emission canister. When the engine is sub-
sequently started, the evaporative emission
canister is gradually purged as air is sucked
into it through a shut-off valve. The hydro-
carbon/air mixture passes through the evap
canister purge valve and into the engine
where it is burned.
When refueling, make sure you screw the
filler cap on and keep turning until it has
clicked at least 3 times. Otherwise, it is pos-
sible for the CHECK ENGINE light to illumi-
nate and a “TIGHTEN FUEL FILLER CAP“
message to appear on SID.
Refueling, see page 134.
Engine
2.3-liter engine
The 2.3-liter model is a transverse, 4-cylin-
der in-line engine with twin overhead cam-
shafts and 4 valves per cylinder.
This engine is equipped with balance shafts
that reduce engine vibration to a minimum.
The balance shafts are chain driven and
rotate at twice the speed of the crankshaft.
They produce forces and torques that are
opposed to those generated by the pistons
and connecting rods, an effect that occurs
twice for each revolution of the engine.
Engine noise is also reduced as the
counter-rotating shafts counteract the vibra-
tion from the moving parts of the engine.
The transmission, located on the right
(viewed from the front), is integrated with
the engine. All models have front-wheel
drive.
3.0-liter V6 engine
The 3.0-liter engine is a transverse, V6
engine with each bank of cylinders having
double overhead camshafts and 4 valves
per cylinder.
The transmission, located on the right
(viewed from the front), is integrated with
the engine. All models have front-wheel
drive.
IB601
Balance shafts, 4-cyl. engine